Hi. I am doing an agarose gel electrophoresis. After running PCR samples in a 2% agarose gel at 90V x 45' I obtained the results in the image.

The ladder bands are not properly stained. For example, the bands at the bottom have more intensity than the reference (500bp). Using another DNA marker I got similar results.

I am using a recent GelRed added during the gel preparation at 0.1X concentration (which worked fine before). Increasing the concentration to 1X resulted in all ladder bands being very bright. The DNA marker used is brand new. The TBE used was new.

Why are the bands not staining properly? Thanks.

More Renato Daniel La Torre Ramírez's questions See All
Similar questions and discussions